Color, microstructure, physicochemical, textural and sensory properties with the retention of secondary metabolites in convective-, microwave- and freeze-dried carrot (Daucus carota) slices

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gulcin Yildiz
Keyword(s):  
Secondary Metabolites ◽  
Freeze Drying ◽  
Quality Characteristics ◽  
Sensory Properties ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Content Type ◽  
Freeze Dried ◽  
The Impact

Purpose This work was undertaken to evaluate the impact of different drying methods (convective, microwave and freeze drying) on color, selected secondary metabolites (total phenolic substances, ascorbic acid, beta-carotene and antioxidant capacity), texture (hardness), sensory properties and microstructure of carrot slices.Design/methodology/approachConvective drying at three different temperatures (55, 65 and 75 °C), microwave drying at two different power levels (100 and 200 W) and freeze drying were applied.FindingsSignificant differences were found among fresh and dried-carrot slices. Convective-dried carrots showed better quality characteristics in comparison with microwave-dried carrots. The convective-dried carrots at 65 °C exhibited the highest retention of bioactive compounds and best color among all convective drying conditions. The microwave-dried carrot slices at lower power (100 W) showed higher quality characteristics compared to the dried carrots at 200 W. The freeze-dried carrots exhibited the highest retention of secondary metabolites, sensory properties and best color among all drying methods.Originality/value The results from this study are significant for the processing of dried carrots by optimizing the conditions to obtain a high-quality product. Overall, freeze drying is a promising application as shown in the present study by its capability to better retention carrot quality underlying color, sensory, texture, microstructure and secondary metabolites.

scholarly journals Effect of Drying Methods on Properties of Potato Flour and Noodles Made with Potato Flour

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1115
Author(s):  
Huan Bao ◽  
Jiaping Zhou ◽  
Jinglin Yu ◽  
Shujun Wang
Keyword(s):  
Freeze Drying ◽  
Quality Characteristics ◽  
Drying Methods ◽  
Potato Flour ◽  
Starch Granules ◽  
Ordered Structure ◽  
Fresh Potato ◽  
Structural And Functional Properties ◽  
The Impact

This work investigated the impact of three drying methods on structural and functional properties of potato flour (PF), as well as the quality characteristics of fresh noodles made from wheat-potato flours. The results indicated that ethanol drying (ED) and oven drying (OD) had small effects on the properties of starch in potato flour, however, freeze drying (FD) caused some pores and channels on the starch granules and disruption of the long- and short-range ordered structure of starch. The maximum addition of potato flour in fresh noodles was 40% for FD-PF and 50% for both ED-PF and OD-PF. With increasing addition of potato flour in noodles, the L* (lightness) values of noodles decreased gradually, while the a* (redness) and the b* (yellowness) values, as well as the hardness and springiness values of fresh potato noodles increased. This study clearly showed that drying methods have different effects on the properties of potato flour, and in turn the quality of fresh noodles made with potato flour.

scholarly journals Effects of drying methods on the physicochemical properties and antioxidant capacity of Kuini powder

2021 ◽  
Vol 24 ◽  
Author(s):  
Gan Wei Shuen ◽  
Lew Yan Yi ◽  
Thor Sing Ying ◽  
Germaine Chng Yu Von ◽  
Yus Aniza Binti Yusof ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Colour Change ◽  
Carotenoid Content ◽  
Total Phenolic ◽  
Drying Methods ◽  
Vacuum Oven ◽  
Oven Drying ◽  
Convection Oven ◽  
Total Carotenoid Content ◽  
Freeze Dried

Abstract Kuini powders were obtained through spray-drying, freeze-drying, vacuum oven drying and convection oven drying. Colour, water activity (Aw), moisture content, hygroscopicity, wettability, flowability, degree of caking, water solubility index (WSI), total colour change, total phenolic content and total carotenoid content of Kuini powders were determined and compared. Convection oven drying resulted in the highest yield (46.97%), moisture content (4.91%), Aw (0.55) and WSI (74.33%) among all the drying methods. However, convection oven-dried Kuini powder had the lowest hygroscopicity and wettability, which were 18.66% and 12.04 s, respectively. Spray drying resulted in poor hygroscopicity (22.41%), degree of caking (22.16%), wettability (275s), WSI (45.67%) and higher colour change (59.81). Least total colour change (19.05) and higher yellowness (57.31) were observed in freeze-drying. In addition, freeze-dried Kuini powder had the highest total phenolic content (24.76 mg/100 g) and total carotenoid content (1.61 mg/100 g). Drying temperature had a negative and significant correlation with the retention of color pigments and antioxidant content. The physicochemical properties and antioxidant content of freeze-dried Kuini powder were preferred over spray-dried, vacuum oven-dried and convection oven-dried powders. Hence, freeze-drying offers potential application in the food products.

scholarly journals Convective Drying of Fresh and Frozen Raspberries and Change of Their Physical and Nutritive Properties

Foods ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 251 ◽  
Author(s):  
Zoran Stamenković ◽  
Ivan Pavkov ◽  
Milivoj Radojčin ◽  
Aleksandra Tepić Horecki ◽  
Krstan Kešelj ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Freeze Drying ◽  
Color Change ◽  
Quality Criteria ◽  
Ascorbic Acid Content ◽  
Biologically Active ◽  
Convective Drying ◽  
Total Phenolic ◽  
Anthocyanin Content ◽  
Freeze Dried

Raspberries are one of Serbia’s best-known and most widely exported fruits. Due to market fluctuation, producers are looking for ways to preserve this fresh product. Drying is a widely accepted method for preserving berries, as is the case with freeze-drying. Hence, the aim was to evaluate convective drying as an alternative to freeze-drying due to better accessibility, simplicity, and cost-effectiveness of Polana raspberries and compare it to a freeze-drying. Three factors were in experimental design: air temperature (60, 70, and 80 °C), air velocity (0,5 and 1,5 m · s−1), and state of a product (fresh and frozen). Success of drying was evaluated with several quality criteria: shrinkage (change of volume), color change, shape, content of L-ascorbic acid, total phenolic content, flavonoid content, anthocyanin content, and antioxidant activity. A considerable influence of convective drying on color changes was not observed, as ΔE was low for all samples. It was obvious that fresh raspberries had less physical changes than frozen ones. On average, convective drying reduced L–ascorbic acid content by 80.00–99.99%, but less than 60% for other biologically active compounds as compared to fresh raspberries. Convective dried Polana raspberry may be considered as a viable replacement for freeze-dried raspberries.

scholarly journals The Effect of Different Drying Methods on Primary and Secondary Metabolites in Korean Mint Flower

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 698
Author(s):  
Chang Ha Park ◽  
Hyeon Ji Yeo ◽  
Chanung Park ◽  
Yong Suk Chung ◽  
Sang Un Park
Keyword(s):  
Amino Acids ◽  
Secondary Metabolites ◽  
High Performance ◽  
Freeze Drying ◽  
Sinapic Acid ◽  
Drying Methods ◽  
Oven Drying ◽  
Primary And Secondary Metabolites ◽  
Freeze Dried ◽  
Β Carotene

Edible flowers have been used in the food and beverage industries because of their high nutritional value, flavor, and scent. For the storage of edible flowers used in these industries, drying is a necessity to store the materials more easily and prevent the damage of metabolites in the flowers. However, drying may affect metabolite retention because drying conditions can differ according to the various methods. In this study, Agastache rugosa flowers were dried using four different methods (oven drying at 25 ± 1 °C, 50 ± 1 °C, 80 ± 1 °C, and freeze drying) and primary and secondary metabolites were analyzed using high-performance liquid chromatography (HPLC) and gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). Freeze-dried flower samples contained higher levels of carotenoids (lutein, 13Z-β-carotene, β-carotene, and 9Z-β-carotene) and phenolics (rosmarinic acid, ferulic acid, and sinapic acid). Contrarily, the 80 °C oven-dried flower samples contained higher levels of most amino acids and flavonoids (including acacetin and tilianin) and at 25 °C and 50 °C contained higher levels of carbohydrates. Therefore, freeze-drying is a suitable method for retaining carotenoids and phenolics. In contrast, oven drying at 50 °C was highly recommended to retain amino acids and flavonoids.

Effect of different drying methods on quality attributes of beetroot (Beta vulgaris) slices

2018 ◽  
Vol 15 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Manhal Gobara Hamid ◽  
Abdel Azim Ahmed Mohamed Nour
Keyword(s):  
Chemical Composition ◽  
Beta Vulgaris ◽  
Quality Attributes ◽  
Rich Source ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Content Type ◽  
Oven Drying ◽  
Freeze Dried

PurposeThe purpose of this paper is to evaluate the effect of different drying methods on quality attributes of beetroot slices.Design/methodology/approachThree drying methods (sun, oven and freeze-drying) were applied to dry fresh slices of beetroot cultivar (Beta vulgaris). The chemical composition, minerals, nitrate, betalains, total phenolic, total flavonoid and color were measured for fresh and dried slices.FindingsThe chemical composition, minerals, nitrate, bioactive compounds and color were measured for fresh and dried slices. Regardless of the drying method, the results showed that the chemical composition, total energy, minerals and nitrate of the dried slices were significantly (p=0.05) increased compared to that of fresh slices. Sun and oven drying of the slices significantly (p=0.05) reduced total betalain and betacynin. However, betaxanthin was significantly (p=0.05) increased. Total phenolics content of fresh beetroot was significantly (p=0.05) increased after sun and oven drying but total flavonoids were decreased. The 2,2,-diphenyl-2-picryl-hydrazyl (DPPH) of fresh beetroot was increased significantly (p=0.05) after sun and oven drying. The measurement of the color of the powder showed that there is a decrease in lightness (L) depending on the drying method applied. A maximum reduction in lightness was observed in powder of sun-dried slices. The color of the powder obtained from freeze-dried slices was stable compared to other drying methods.Practical implicationsBeetroot is a rich source of nutrients but with short shelf life. Dried beetroot has more keeping quality than the fresh one.Originality/valueThe study uses beetroot as a rich source of nutrients as well as natural antioxidant source. Betalain compounds are preserved in beetroot and a high source of phenolics and flavonoids. Flavonoids are a group of phenolic products of plant metabolism with high antioxidant properties to protect against diseases without side effects.

scholarly journals Hydroxycinnamic Acids and Carotenoids of Dried Loquat Fruit cv. ‘Algar’ Affected by Freeze-, Convective-, Vacuum-Microwave- and Combined-Drying Methods

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3643 ◽  
Author(s):  
David Bernardo López-Lluch ◽  
Marina Cano-Lamadrid ◽  
Francisca Hernández ◽  
Aleksandra Zimmer ◽  
Krzysztof Lech ◽  
...  
Keyword(s):  
Quinic Acid ◽  
Hydroxycinnamic Acids ◽  
Convective Drying ◽  
Carotenoid Content ◽  
Drying Methods ◽  
Antioxidant Power ◽  
Vacuum Microwave ◽  
Freeze Dried ◽  
The Impact ◽  
Caffeoyl Quinic Acid

The effect of different drying techniques (freeze, convective, vacuum-microwave and combined drying) on the drying kinetics, the phytochemical compounds and sensory characteristics in loquat cultivar ‘Algar’ was studied. The convective drying resulted in the highest amount of total hydroxycinnamic acids (5077 mg/kg wet weight (ww)), with 3-caffeoyl quinic acid and 5-caffeoyl quinic acid being the greatest carotenoids. The highest values of total carotenoids were obtained by the freeze-drying technique (2601 mg/kg ww), followed by all convective treatments and vacuum-microwave at 360 W. The highest carotenoid was β-carotene. The ABTS+• (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (Ferric Ion Reducing Antioxidant Power) values ranged from 2.04 up to 3.27 mmol Trolox/100 g ww, and from 1.89 up to 2.29 mmol Trolox/100 g ww, respectively. As expected, the color difference of freeze-dried samples was the lowest (7.06), similar to combined drying conditions (9.63), whilst the highest value was found after convective drying (37.0). All treatments were sensory acceptable (no off-flavors). However, still, further research is needed to fully optimize these studied drying treatments because the freeze-dried sample still had higher carotenoid content and better instrumental color parameters. Although recently the impact of microwave drying has been studied, this is the first work comparing phytochemical composition of loquat fruit under the different drying methods mentioned above.

scholarly journals Investigation of the Most Suitable Conditions for Dehydration of Tuckeroo (Cupaniopsis anacardioides) Fruits

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 151
Author(s):  
Ngoc Minh Quynh Pham ◽  
Quan V. Vuong ◽  
Anh V. Le ◽  
Michael C. Bowyer ◽  
Christopher J. Scarlett
Keyword(s):  
Antioxidant Activity ◽  
Freeze Drying ◽  
Large Scale ◽  
Total Phenolic ◽  
Drying Methods ◽  
Hot Air ◽  
Antioxidant Characteristics ◽  
High Level ◽  
The Impact ◽  
Gallic Acid Equivalent

Tuckeroo (Cupaniopsis anacardioides) is an Australian native tree, possessing high level bioactivity and antioxidant activity. To prevent deterioration of active constituents, appropriate drying practices must be determined. This study comparatively evaluates the impact of a range of drying methods including freeze-, microwave-, vacuum-, hot air- and sun-drying on the physical, phytochemical and antioxidant characteristics of Tuckeroo fruit. Experimental results showed that the five drying methods had significant impact on the physicochemical properties and antioxidant activity of the fruits. Of the drying methods assessed, freeze drying best preserved Tuckeroo activity, recording higher total phenolic content (TPC) (81.88 mg gallic acid equivalent (GAE)/g), total flavonoids (TFC) (107.71 mg catechin equivalent (CAE)/g), proanthocyanidins (TPro) (83.86 mg CAE/g) and exhibited the strongest antioxidant capacity. However, vacuum drying at 65 kPa, 100 °C for 5 h is recommended for drying Tuckeroo fruits for further processing in a large scale as it also retained high levels of TPC, TFC and TPro (58 mg GAE/g, 91 mg CAE/g and 74 mg CAE/g, respectively).

scholarly journals Effect of Different Drying Techniques on the Resistant Starch, Bioactive Components, Physicochemical and Pasting Properties of Cardaba Banana Flour

2019 ◽  
Vol 23 (1) ◽  
pp. 35-42
Author(s):  
Adedolapo Ibironke Falodun ◽  
Helen Nwakego Ayo-Omogie ◽  
Olugbenga Olufemi Awolu
Keyword(s):  
Freeze Drying ◽  
Antioxidant Properties ◽  
Pasting Properties ◽  
Total Phenolic ◽  
Drying Methods ◽  
Crude Fibre ◽  
Freeze Dried ◽  
Drying Techniques ◽  
Flour Sample ◽  
Banana Flour

Abstract This study investigated the effect of different drying techniques on Cardaba banana flour. Cardaba banana was processed using sun, cabinet and freeze drying methods. The proximate, pasting, functional, starch profile and antioxidant properties of Cardaba banana flour were evaluated. The drying methods significantly (p ≤0.05) affected the chemical, functional, pasting and antioxidant properties of the Cardaba banana flour. Freeze dried (FD) flour sample had highest (6.69%) protein value, while sun dried (SD) flour sample had the lowest (6.13%). The crude fat of FD sample (2.38%) was not significantly different (p >0.05) from cabinet dried (CD) flour (2.38%) sample. However, sun dried sample crude fibre content was the highest (0.84%). In addition, drying methods significantly (p ≤0.05) affected the pasting characteristics of Cardaba banana flours. Results of functional properties showed that the drying methods had no effect on the least gelation properties of the flour. The resistant and total starch was highest in CD, and least in SD. Freeze drying produced flour high in indigestible carbohydrate compared to the other methods. Cardaba banana flour samples from all the drying methods showed substantive total phenolic, flavonoid, ABTS and DPPH contents. The drying methods employed significantly (p ≤0.05) affected the functional, chemical, pasting and antioxidants properties of Cardaba banana flours. However, the study indicated that freeze drying and cabinet drying produce flours with better properties.

scholarly journals Response of Nutritional and Phytochemical Constituents of Bitter Leaf to Some Drying Methods

2019 ◽  
pp. 1-10
Author(s):  
Johnson Odukoya ◽  
Uzoma Charles ◽  
Julianah Odukoya
Keyword(s):  
Vitamin A ◽  
Freeze Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Vegetable Samples ◽  
Chemistry Research ◽  
Freeze Dried ◽  
Significant Difference ◽  
Dietary Minerals ◽  
The Impact

Aim: Food processing is one of the post-harvest factors that affect the quality of food products. This research was aimed at evaluating the impact of two drying methods (sun-drying and freeze-drying) on the nutritional and phytochemical contents of Vernonia amygdalina Del. Study Design: Processed vegetables of V. amygdalina were subjected to the selected drying methods and the composition of the dried samples was thereafter compared. Place and Duration of Study: The eight-month study was carried out at the Food Chemistry Research Laboratory, Chemistry Department, The Federal University of Technology, Akure, Ondo State, Nigeria. Methodology: Harvested fresh samples of V. amygdalina were first cleaned with distilled water prior to drying. The dried vegetable samples were then ground to powder and subjected to proximate analysis via the application of recommended methods of Association of Official Analytical Chemists. Other nutritional and phytochemical analyses were achieved using standard methods. Independent-samples t-test was used to compare the difference in composition. Results: The results showed that except for crude fibre content, there was a statistical significant difference (p < 0.05) in the proximate composition of the vegetable samples obtained from the two drying methods while the freeze-drying method favoured the concentration of most of the dietary minerals tested. The two drying methods were found to give a similar phytochemicals screening result with the sun-dried samples having a higher concentration of total phenols and total flavonoids. The freeze-dried samples, however, had higher vitamin A and C contents. Conclusion: The research outcome revealed the suitability of the freeze-drying method for enhanced/improved drying action on vegetables and to have the optimum level of crude protein, major dietary minerals, vitamin A and C in the dried vegetables. Further work is needed to assess the impact of the selected drying methods on antinutrients composition.

scholarly journals Effect of Freeze Drying and Simulated Gastrointestinal Digestion on Phenolic Metabolites and Antioxidant Property of the Natal Plum (Carissa macrocarpa)

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1420
Author(s):  
Faith Seke ◽  
Vimbainashe E. Manhivi ◽  
Tinotenda Shoko ◽  
Retha M. Slabbert ◽  
Yasmina Sultanbawa ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Array Detector ◽  
Gastrointestinal Digestion ◽  
Liquid Chromatograph ◽  
Antioxidant Power ◽  
Intestinal Phase ◽  
Glucosidase Activity ◽  
Freeze Dried ◽  
Small Intestinal ◽  
The Impact

Natal plums (Carissa macrocarpa) are a natural source of bioactive compounds, particularly anthocyanins, and can be consumed as a snack. This study characterized the impact of freeze drying and in vitro gastrointestinal digestion on the phenolic profile, antioxidant capacity, and α-glucosidase activity of the Natal plum (Carissa macrocarpa). The phenolic compounds were quantified using high performance liquid chromatography coupled to a diode-array detector HPLC-DAD and an ultra-performance liquid chromatograph (UPLC) with a Waters Acquity photodiode array detector (PDA) coupled to a Synapt G2 quadrupole time-of-flight (QTOF) mass spectrometer. Cyanidin-3-O-β-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside (Cy-3-G) were the dominant anthocyanins in the fresh and freeze-dried Natal plum powder. Freeze drying did not affect the concentrations of both cyanidin compounds compared to the fresh fruit. Both cyanidin compounds, ellagic acid, catechin, epicatechin syringic acid, caffeic acid, luteolin, and quercetin O-glycoside from the ingested freeze-dried Natal plum powder was quite stable in the gastric phase compared to the small intestinal phase. Cyanidin-3-O-β-sambubioside from the ingested Natal plum powder showed bioaccessibility of 32.2% compared to cyanidin-3-O-glucoside (16.3%). The degradation of anthocyanins increased the bioaccessibility of gallic acid, protocatechuic acid, coumaric acid, and ferulic acid significantly, in the small intestinal digesta. The ferric reducing antioxidant power (FRAP), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) activities, and inhibitory effect of α-glucosidase activity decreased in the small intestinal phase. Indigenous fruits or freeze-dried powders with Cy-3-Sa can be a better source of anthocyanin than Cy-3-G due to higher bioaccessibility in the small intestinal phase.

Sign in / Sign up

Export Citation Format

Share Document